Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L33/00—Arrangements for connecting hoses to rigid members; Rigid hose connectors, i.e. single members engaging both hoses
  • F16L33/01—Arrangements for connecting hoses to rigid members; Rigid hose connectors, i.e. single members engaging both hoses adapted for hoses having a multi-layer wall
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/04—Hoses, i.e. flexible pipes made of rubber or flexible plastics
  • F16L11/08—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall
  • F16L11/081—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire
  • F16L11/083—Hoses, i.e. flexible pipes made of rubber or flexible plastics with reinforcements embedded in the wall comprising one or more layers of a helically wound cord or wire three or more layers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L11/00—Hoses, i.e. flexible pipes
  • F16L11/20—Double-walled hoses, i.e. two concentric hoses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L2201/00—Special arrangements for pipe couplings
  • F16L2201/30—Detecting leaks

Definitions

• TITLE FLEXIBLE CONDUCT FOR THE TRANSPORT OF A FLUID IN THE ENVIRONMENT
• the invention relates to the technical field of flexible pipes for transporting a fluid in an underwater environment.
• the invention relates to unbound flexible pipes used for the transport of hydrocarbons in an underwater environment.
• Flexible pipes for transporting a fluid in an underwater environment are submerged in a body of water at depths that can exceed 3000 m. They are particularly useful in the delivery of water and / or hydrocarbons between a downhole installation and a surface installation. They can also be used to connect two downhole installations. Some flexible pipes can also be used to connect two surface installations.
• a flexible pipe comprises an internal sealing sheath called in the technical field of the invention "pressure sheath".
• the internal sealing sheath forms an internal passage for the circulation of the fluid and thus ensures its transport in a sealed manner.
• a pair of tensile armor plies is arranged around the internal sheath to take up these tensile forces.
• the pair of tensile armor plies are typically composed of coiled metal wires helical with a long pitch, that is to say that the absolute value of the helix angle is between 20 ° and 55 °.
• the latter In order to prevent the entry of water from the body of water into the flexible pipe, the latter generally includes a protective polymeric outer sheath arranged around the pair of tensile armor plies.
• the outer sheath generally has a thickness of 10 mm.
• the inner sheath and the outer sheath define a space called the annular space.
• the pair of tensile armor plies are arranged within the annular space.
• the fluid transported is generally composed of crude hydrocarbons. These hydrocarbons generally include a mixture of gases such as carbon dioxide, methane or even hydrogen sulfide.
• the transported fluid also includes water and possibly sand particles.
• the gases contained in the transported fluid diffuse through the internal sheath and accumulate within the annular space.
• the annular space also includes water which results from an accidental loss of sealing of the outer sheath and / or from the diffusion and condensation of water contained in the fluid carried through the inner sheath.
• the presence of water and these gases within the annular space causes various corrosion phenomena of the metal armor wires within the annulus.
• the armor wires can then be subjected, for example, to stress corrosion cracking ("Stress Corrosion Cracking, SCC").
• WO2009 / 007670 describes an inspection method aimed at detecting the presence of water in the annular space of a flexible pipe.
• This method is based on an ultrasonic ultrasound technique.
• An ultrasonic wave is sent into the annular space of the flexible pipe through the outer sheath using an ultrasonic transducer disposed outside the flexible pipe and in the vicinity of the polymeric outer sheath of the flexible pipe.
• This wave is partially reflected in the annular space, in particular by the metal armor, the intensity of the reflected wave depending on the possible presence of water in the annular space.
• the ultrasonic transducer measures the wave reflected and echogram analysis can detect the possible presence of water in the ring finger.
• This inspection method is insufficiently reliable, especially when the outer sheath of the flexible pipe is thick and made of a polymeric material which strongly absorbs ultrasound.
• the invention relates to a flexible pipe for transporting a petroleum fluid in an underwater environment
• a flexible tubular section and two end fittings, each of the two ends of said flexible tubular section being connected to a of said two end caps.
• Said flexible tubular section includes from the inside to the outside a polymeric inner sheath to form a fluid circulation passage, at least one armor layer, and a polymeric outer sheath.
• Said inner sheath and outer sheath define an annular space in which said at least one layer of armor is arranged.
• Each of said two end fittings comprises from the inside to the outside an end vault connected in a sealed manner to said internal sheath to form a passage for the circulation of the petroleum fluid, means for anchoring said at least one layer of armor, and a metal hood. Said cover is fixed to said end vault and is sealingly connected to said outer sheath.
• at least one of said two end fittings comprises a cavity connected to said annular space by communication means, said communication means being able to circulate water from said annular space to said cavity , said cover forming the outer wall of said cavity, so that it is possible to detect the presence of water in said annular space by inspecting said cavity with an ultrasonic transducer placed outside said cover in line with said cavity.
• the invention is characterized on the one hand by the addition in at least one of the two end fittings of a cavity communicating with the annular space of the flexible pipe, and on the other hand by the fact that this cavity is disposed just below the metal cover of the end cap.
• This cavity is initially filled with air when the annular space is dry. If the annular space becomes flooded when the pipe is in service, then the cavity fills with water and it is therefore possible to indirectly detect the presence of water in the pipe. the annular space by detecting the presence of water in the cavity.
• the cap of the nozzle being metallic, it can easily be crossed by an ultrasonic wave, with a very low attenuation, and it is therefore possible to make a reliable detection of the presence of water in the cavity by using a ultrasound ultrasound method operate from the outer face of the flap to the right of the cavity.
• the fact that the outer wall of the cavity is the cap of the nozzle simplifies the structure of the nozzle and therefore reduces its cost, by avoiding the addition of additional parts, in particular by avoiding the addition of a waterproof cover separate from the bonnet in order to isolate the mouthpiece cavity from the outer space.
• the metal cap of the nozzle which has the function of sealingly isolating the cavity from the external space, which not only makes it possible to simplify the structure of the nozzle, but also to '' obtain a very resistant and perfectly sealed outer cavity wall. It is essential that the outer wall of the cavity be perfectly sealed, because a loss of sealing of the outer wall of the cavity would cause the cavity to be flooded with seawater, and this seawater would then flood the water. annular space of the flexible tubular section flowing along the communication means.
• the use of the end cap cover as the outer wall of the cavity provides a simple, robust and reliable solution.
• said cavity is located in front of said anchoring means.
• front side is meant the side furthest from the flexible tubular section to which the end fitting in question is connected.
• the cavity can be integrated into the nozzle without having to increase the outer diameter of the nozzle.
• rear side is meant the side closest to the flexible tubular section to which the end piece in question is connected.
• said cover has a constant thickness in line with said cavity.
• the thickness of said cover in line with said cavity is between 10 mm and 60 mm.
• said cavity has a volume of between 0.1 and 10 liters, preferably between 1 and 10 liters.
• said end vault forms the inner wall of said cavity.
• said cavity is axisymmetric and coaxial with the central longitudinal axis of said at least one end cap.
• the internal and external faces of said cavity are cylindrical and coaxial. This makes it possible in particular to obtain a cavity of annular geometry going all the way around the tip. This feature facilitates ultrasonic inspection of the mouthpiece when it is resting on the seabed and sometimes partially buried.
• this part necessarily comprises a part of the cover situated in line with the cavity, which makes it possible ultrasonic inspection to detect the presence of water in the annulus.
• the various interfaces crossed by the incident ultrasonic wave are cylindrical surfaces, in particular the outer and inner faces of the cover forming the outer wall of the cavity, as well as the outer face of the inner wall of the cavity.
• the incident ultrasonic wave propagates radially from the outside to the inside of the end piece, and the ultrasonic waves reflected by the various interfaces propagate radially towards the outside of the end piece following the same radius as that followed by the incident wave.
• the reflected waves are sent back to the ultrasonic transducer which can therefore easily detect and measure the associated echoes.
• it is possible to obtain good quality signals which improves the reliability of the detection of the presence of water in the cavity.
• the internal and external faces of said cavity are plane and parallel.
• This variant makes it possible to use an ultrasonic control method in which the incident wave emitted by the ultrasonic transducer propagates in a direction perpendicular to the plane faces, so that the waves reflected by these faces are returned in the same direction to the ultrasonic transducer.
• the waves reflected by the cavity can thus be easily detected and precisely measured by the transducer, which improves the reliability of the presence of water in the cavity.
• the subject of the invention is also a method of in-service inspection of a flexible pipe for the transport of a fluid in an underwater environment, said method comprising the following steps:
• step (e) analyzing said ultrasonic signal to determine whether said cavity is filled with air or water, so as to determine the absence or presence of water in the annular space of said flexible pipe.
• said transducer is in direct contact with the external face of said cover to the right of said cavity.
• step (b) said transducer is not in direct contact with the external face of said cover, the ultrasonic coupling between said transducer and said cover being carried out by sea water.
• step (c) the incident ultrasonic wave is a compression wave which propagates in a radial direction with respect to said at least one end piece.
• FIG. 1 schematically shows a perspective view of an example of a flexible tubular section of a flexible pipe according to the invention
• FIG. 2 schematically shows a partial cross-sectional view of an end cap of a flexible pipe according to the invention
• FIG. 3 schematically shows a partial cross-sectional view of a step of the inspection method according to the invention.
• Figure 1 shows an example of a flexible tubular section (2) of a flexible pipe (1) according to the invention.
• the flexible pipe (1) is intended to be submerged in a body of water.
• the body of water can be a lake, sea, or ocean.
• the depth of the body of water is at least 100 m, and more particularly between 500 m and 3000 m.
• the flexible pipe (1) carries a fluid through the body of water between a first installation and a second installation.
• the first installation is for example an underwater installation such as a well head or a manifold (called a “manifold” in English).
• the second installation is, for example, a surface installation such as a floating production, storage and offloading unit (FPSO for “Floating Production Storage and Offloading”) or a tensioned anchoring platform (TLP for “Tension Leg Plaftorm ”in English).
• FPSO floating production, storage and offloading unit
• TLP tensioned anchoring platform
• the fluid transported by the flexible pipe (1) is for example water and / or a petroleum and / or gas fluid.
• the petroleum and / or gas fluid is formed from a multiphase mixture comprising a liquid part formed mainly of linear and / or cyclic carbon compounds, saturated and / or unsaturated, of variable density and water, a gaseous part composed for example of methane (CH4), carbon dioxide (C02), hydrogen sulphide (H2S) and other gases and finally, a solid part generally composed of particles of sand.
• the temperature of the fluid within the flexible pipe (1) is between 50 ° C and 200 ° C, more particularly between 50 ° C and 130 ° C. The temperature of the fluid varies during transport between the first installation and the second installation.
• the fluid has, for example, a partial pressure of carbon dioxide of between 1 bar and 300 bar and a partial pressure of hydrogen sulfide of less than 1 bar.
• the partial pressure of each of the gases within the fluid depends in particular on the nature of the oil and / or gas field being exploited.
• the flexible tubular section (2) of the flexible pipe (1) comprises a plurality of concentric layers arranged around a longitudinal axis.
• the flexible tubular section (2) of the flexible pipe (1) comprises an internal polymeric sheath (4), at least one armor layer (5) and an external polymeric sheath (6).
• the flexible pipe (1) is preferably a flexible pipe of the unbound type.
• unbound it is understood within the meaning of the present invention, a flexible pipe (1) in which the armor layer is free to move relative to the internal sheath (4) during a bending of the flexible pipe. (1).
• all the layers of the flexible pipe (1) are free to move relative to one another. This makes the flexible pipe (1) more flexible than a pipe in which the layers are bonded to each other.
• the flexible tubular section (2) of the flexible pipe (1) also comprises an internal carcass (8) arranged inside the internal sheath (4).
• the function of the internal carcass (8) is to take up the radial crushing forces, in particular those related to the hydrostatic pressure.
• the internal carcass (8) is generally formed from a profiled metal strip in the form of an S and wound in turns stapled to each other.
• a flexible pipe (1) comprising an internal carcass (8) is said to have a non-smooth passage (“rough bore” in English).
• a flexible pipe (1) which does not have an internal carcass (8), and in which the innermost layer is the internal sheath (4) is said to smooth passage ("smooth bore” in English).
• the present invention is equally applicable to flexible pipes with a smooth passage and a non-smooth passage.
• the internal sheath (4) is arranged around the internal carcass (8) when the latter is present.
• the internal sheath (4) forms a passage for circulation of the fluid. It ensures the transport of the fluid through the body of water in a sealed manner.
• the inner sheath (4) is polymeric, that is to say that more than 50% of the material forming the inner sheath (4) is a polymer.
• the polymer is for example a polyolefin such as a polypropylene, a polyethylene or a polyamide or else a fluoropolymer such as a polyvinylidene fluoride (PVDF).
• PVDF polyvinylidene fluoride
• the polymeric material is chosen according to the nature and the temperature of the fluid transported.
• the thickness of the internal sheath (4) is for example between 4 mm and 15 mm.
• the internal sheath (4) is produced by extrusion, for example around the internal carcass.
• the at least one armor layer (5) is intended to strengthen the flexible pipe (1) against tensile and pressure forces.
• the flexible tubular section (2) of the flexible pipe (1) advantageously comprises a crossed pair of tensile armor plies wound at a long pitch.
• long step is meant a helix angle of absolute value between 20 ° and 55 °.
• the section of the tensile armor wires is for example rectangular or circular.
• the tensile armor wires are advantageously metallic.
• the metallic material is for example a carbon steel.
• the polymeric outer sheath (6) is arranged around the pair of the at least one armor layer (5).
• the outer sheath (6) is impermeable to liquids and forms a protective barrier against the ingress of water from the body of water inside the flexible tubular section (2) of the flexible pipe (1).
• the outer sheath (6) and the inner sheath (4) define between them an annular space (7).
• the annular space comprises according to the example shown in Figure 1, a pressure vault and a pair of tensile armor plies (5).
• the pressure vault of the flexible tubular section (2) of the flexible pipe (1) is an optional layer of armor wound in short pitch around the internal sheath (4).
• the function of the pressure vault is to increase the resistance to pressure of the flexible pipe (1). It is advantageously made of metal wires in the form of Z, T, K , U or X, whose turns are stapled to each other.
• short pitch it is meant a helix angle of absolute value between 60 ° and 90 °.
• the end piece (3) of the flexible pipe (1) comprises from the inside to the outside an end vault (31) and a cover (33) fixed to the vault end (31).
• the armor layer (s) (5) of the pipe are anchored to the end piece by anchoring means (32) which generally consist of a chamber filled with resin inside which the ends of the wires d. '' weaves are blocked, especially when the armor threads are the traction armor threads wound at a long pitch
• the end vault (31) of the end cap (3) is a substantially tubular, advantageously metallic part, inside which the petroleum fluid circulates. It is connected in a sealed manner to the internal polymeric sheath (4) of the flexible tubular section (2) by means of the internal means of sealed connection (36), so that the petroleum fluid can flow from the inside of the tube. the end vault (31) towards the inside of the flexible tubular section (2) while remaining confined inside the flexible pipe (1).
• the internal sealed connection means (36) advantageously comprise means for crimping the internal sheath (4).
• the cover (33) of the end piece (3) is a substantially tubular piece, advantageously made of metal, sealingly connected to the outer sheath (6) of the flexible tubular section (2) by means of external sealing means. (37).
• the external sealed connection means (37) advantageously comprise means for crimping the outer sheath (6).
• the front end of the end cap (3) advantageously includes a flange (39) allowing the connection of the flexible pipe (1) with external equipment.
• the end vault (31) and the cover (33) advantageously have the same longitudinal axis (38) and are substantially axisymmetric with respect to the longitudinal axis (38).
• the end of the cover (33) which is furthest from the flexible tubular section (2), also called the front end of the cover, is fixed to the end arch (31) by fixing means advantageously comprising a thread (42 ), the cover (33) being screwed onto the end vault.
• Other fixing means can be used to fix the cover (33) to the end vault (31), for example screws.
• O-rings (43) are arranged between the cover (33) and the end arch (31) to ensure the tightness of the attachment between the cover (33) and the end vault (31) and in particular prevent sea water from entering inside the end cap (3) at this fixing.
• the end of the tensile armor plies (5) of the flexible tubular section (2) extends under the cover (33) in the rear part of the end cap (3), and ends between the vault of end (31) and the cover (33).
• the rear part of the end cap (3) is that located on the side of the flexible tubular section (2) to which the end cap (3) is connected.
• the end piece (3) comprises means (32) for anchoring the armor plies (5) which advantageously consist of locking the end of each armor wire, previously deformed in the form of a hook, using an epoxy-type thermosetting resin which has been cast inside the rear part of the wall of the end cap (3).
• the end cap (3) has a cavity (34) located under the cover (33) on the front side of the end cap (3).
• the cover (33) constitutes the outer wall of the cavity (34).
• the end vault (31) constitutes the internal wall of the cavity (34).
• the cavity (34) is axisymmetric and coaxial with the central longitudinal axis (38) of the end cap (3).
• the end piece (3) comprises communication means (35) capable of circulating water from the annular space (7) towards the cavity (34), and which are advantageously made up of at least one tube connecting the annular space (7) to the cavity (34).
• the end piece (3) advantageously comprises means (40) for discharging the air which are in the form of a chamber. (40) connected to the cavity (34) on the side opposite to the means of communication
• the discharge means 40 can be connected with the outside of the pipe, for example via a non-return valve. They can also be completely isolated from the outside, for example via a sealed plug (41), but it is in this case necessary that the volume of the chamber (40) is sufficient to receive the air coming from the cavity (40 ).
• the in-service inspection method of the flexible pipe (1) comprises a step of applying an ultrasonic transducer (45) in the vicinity of the outer face of the cover (33) of the nozzle. end (3), opposite the cavity (34).
• the end cap advantageously has an outer groove (44) located in front of the cavity (34).
• the transducer is operated by a diver or by a remote-controlled underwater robot of the ROV type.
• the ultrasonic test method is advantageously an ultrasound test method.
• the frequency of the ultrasonic transducer is advantageously between 1 MHz and 15 MHz, preferably between 5 MHz and 10 MHz.
• the transducer advantageously generates an incident compression wave (longitudinal wave) which propagates radially inwardly of the end cap (3) and in return measures the wave returned by the cavity (34).
• This returned wave comprises several waves reflected by each of the interfaces crossed by the incident wave, and in particular on the one hand the wave reflected by the interface between the internal face of the cover (33) and the cavity (34), and d 'on the other hand the wave reflected by the interface between the cavity (34) and the external face of the end vault (31).
• the first of these two reflected waves is recorded by the transducer as an entry echo into the cavity, while the second is recorded as an exit echo.
• the incident ultrasonic wave is almost completely reflected at the input interface into the cavity, since ultrasonic waves with a frequency greater than 1 MHz hardly propagate through the cavity. the air. This generates a very strong input echo and no output echo.
• the incident ultrasonic wave can easily propagate within the cavity due to the acoustic properties of the water.
• the amplitude of the input echo decreases sharply and moreover a high amplitude output echo is observed.

Applications Claiming Priority (2)

Publications (1)

Family

ID=71661877

Family Applications (1)

Country Status (5)

Family Cites Families (9)

• 2020
  • 2020-06-22 WO PCT/FR2020/051083 patent/WO2020254775A1/fr active Application Filing
  • 2020-06-22 EP EP20747018.8A patent/EP3987209A1/de active Pending
  • 2020-06-22 BR BR112021025578A patent/BR112021025578A2/pt unknown
  • 2020-06-22 AU AU2020298124A patent/AU2020298124A1/en active Pending
  • 2020-06-22 US US17/620,151 patent/US11774020B2/en active Active

Also Published As

Similar Documents

Legal Events